Cryptococcus neoformans will be cultured in soils and at various time intervals the cells will be examined for cell size, thickness of capsule, viability and infectivity. By manipulating the soil environment we shall study the role of the capsule as a possible extracellular storage organ. Aerosols of soil containing C. neoformans will be exposed to mice with the purpose of studying the sizes of the infectious particle, portal of entry, mode of dissemination and factors leading to the establishment of an infection. Mice infected by the aerosol method will be treated in various manners in attempts to initiate a disease state.